The correct order of reactivity of alkyl halides: ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{Cl}, {\mathrm{CH}}_3{\mathrm{CHClCH}}_3$ and ${\left({\mathrm{CH}}_3\right)}_3\mathrm{CCl}$ towards dehydrohalogenation ?

• Dehydrohalogenation is an elimination reaction that removes a hydrogen halide from a substrate. The reaction is commonly associated with alkene synthesis, but it has broader applications.

According to the Saytzeff's rule, an alkyl halide which gives more stable alkene (highly substituted) must undergo dehydrohalogenation reaction faster than the alkyl halide which gives less stable (less substituted) alkenes. Hence, the reactivity of the alkyl halides follows the order:- Tertiary>Secondary>Primary.